Stefan, this is is hands down one of my favorite homeshop maching channels for cool projects, excellence in technique and clear explanations on how to achieve the most with modest equipment, often modified and enhanced to perfection. This Old Tony would get the nod for most entertaining content, production shenanigans, cool projects, and dubious "Dad Jokes". I admire and reapect you both.
Well, that was serendipitous! I've just picked up a box of 1/4" carbide tool blanks with the intention of grinding a boring bar or two :-):Cheers Stefan.
Just want to thank You again for the excellent tip of re using the Paul Horn mini boringbars! 👍 I never used them before due to price, but now use regrounds extensively. Made a few holders for the lathe and boring head. I like the P Horn holding system better than the others I had, I am actually quite impressed by the stability and depth of cut that works despite their tinynes... Easy to change tools as well. Found a 16mm MEGA holder (B105.0016.01) that is offset and perfect for regrinding and relieving in the D-bit grinder, the offset is usually perfect for reliefs when re purposing an old insert.
Hallo Stefan. Das ist ein sehr anschauliches video. Vielen Dank für die Erklärung. Nebenbei ist es auch dein bestes Video bis jetzt. Sehr schön erklärt und auch gut geschnitten. Gruß Larry
Great video and interesting take on small carbide tools. Very cool little machine for grinding. Years ago we did similar tools by hand on the basic “bench” diamond grinders with adjustable tables. That always involved an acid brush full of kerosene for coolant flying in your face to keep the diamond wheel clean. A hand-held die grinder with a small diamond wheel was used for adding chip breakers, etc. l get the carbide rigidity thing but still like the idea of custom carbide-tipped tools and high-speed too. Keep up the good work!
Excellent tutorial. I do not have a cutter grinder but have made similar tiny boring bars by hand on the grinder in HSS. A bit crude but with some honing they usually work OK. Thanks for sharing. regards from the UK
Thank you for sharing this important content with us i never have seen a bad video from you and I have never not learned from a video from you so I am grateful for what you're doing and hope you keep on doing this good work 👍😏
An excellent video - both instructional content and close-up camera work. Those two long boring bars (at 7 mins.) with the TiN coating and angled rear alignment surface are Sandvik CXS series - I like them because they are very easy to make the tool holders for, compared with the pHorn style.
Thanks a lot for this very valuable video! I just bought 2 of these very same grinders, one for my own shop and one for a company I do work for. Made the decision based on Yours and Robins videos. Making carbide boring bars seems really useful to me. My production of raw material for these is in the mill is no problem... Also intend to try a CBN cup to decrease dust and perhaps get a bit more repeatability over a number of parts. Present project is to facet grind some very small parts with tight tolerances in some different hardened steels. Btw I ordered 6 extra wheel holders, they are under 30 euros each.
Great video! I have purchased a single lip cutter grinder per your influence. Have all ready used it for projects. I would love to see you use it more on videos to expand my uses for it.
Great timing Stefan. I'm just in the process of grinding some special shaped lathe tools and need to go beyond the 90/0 degrees for the relief. Examining my Chinese DBit grinder I can now see how to do it. The Cinglish 'manual' has no mention of how to. Although a different method is used, once you showed how, it's now blindingly obvious.
what kind of diamond wheels are those again? And, more importantly, how do you dress them? I've got a couple of cheap import ones and they're all loaded up and black now... though they did completely EAT carbide for breakfast when they cut.
My wheels come from an Ukrainian manufacturer - I generaly use two grits, D126 for roughing and D40 for finishing. I usualy dress them with a piece of molybdenium, followed by the sharpening stick, to dress the resin binder back and make the wheel cut again. If a cup wheel is off very much, you can also lap it flat on a piece of glas with Silicone carbide lapping compound. I showed that in a video earlier this year ;)
I only use miniature Sherline and Taig lathes for my model engineering projects ( the old Myford doesn't get used much these days ) and I now only use the Sandvik CXS boring bars , the ones you showed with the gold coating . They work very well on a small machine and can be used on holes from 4mm up wards. I have had no luck trying to grind tools using broken bits of tooling on a bench grinder. I guess that I am not just very good. LOL.
Thanks Stefan, I see you are channeling GH Thomas Just last night at work I was reading through his book and read the section on boring bars, he described making small boring bars the same way but from HSS. Thanks for sharing Cheers
Hello Stefan. Great educational video. I also use a similar D-bit grinder and like their versatility very much. in my eyes they are a good and helpful shop tool, esp. when you need to create/sharpen a tool right now :)
Very good presentation of how to use the d-bit grinder to make small boring bars. Could you please do a similar video of how you ground your mini dovetail cutter for machining the dti holder.
Very cool. Someday I will grind my own small carbide boring bars but until then I will stick with my Circle Machine carbide boring bars. You will be amazed at what they can do. Circle Machine guarantees a 10:1 ratio with moderate feeds and believe me they can do it. I have a 5/32” (4MM) CM bar that takes miniature CDCD inserts with either a .002 or .007” nose radius and have had no issues boring 1.5”. I got it all for about $100 with a handful of inserts. Look for them on Ebay. You can find them in metric too and they use the same inserts
Hi Stefan - this was a great video. I'd love to learn more about what the various carbide grades are and how they compare to some of the cheaper tooling available. e.g. Banggood's "Carbide steel". Which to me is an oxymoron. If you have any videos on this topic, please let me know. Thanks, Craig
Very informative! I"ll probably never have a use for this information (LOL), but I still love learning about it. I really liked this video as is the case with probably every video you've made, honestly and I'm pretty sure I've watched all of them. One of these days I'll get around to getting some basic metal working equipment, but the house I live in now has ANCIENT wiring and I literally have fuses and not breakers (15A for the wall plugs, and a 30A for the washer/drier). Yeah we gotta fix that, but the house will be sold in the next year or two and I'll be in a different one with up-to-date wiring and a nice heated workroom in the basement. What would you recommend if I had to get one thing, a smallish lathe or a milling machine? I've always wanted a small lathe for making metal parts. I absolutely LOVED using my woodshop class wood carving lathe even though the tools were crap and the lathe was not exactly treated well by the High School kids. Once I get all my debts paid off, I'll probably get a lightly used lathe and mill locally haha. We'll see - it's all a dream now, but a completely reasonable one if I get my sh*t together with my money - I make plenty, but spent more. Stupid credit cards, it's all their fault - I take no responsibility! /s
The PH Horn bars look very nice and you can get them in bunches, but I couldn't find a toolholder anywhere and couldn't make one in a hurry so I went with the Micro100 ones...They have a much simpler toolholder with comparable repeatability and their only downfall is being imperial sizes. They offer blanks too! PS: Since I made a 1/8" toolholder I silver braze tiny carbide tips on the tool steel shanks of PCB drills and it works great. Also the deep neck is used to avoid torsion and thus prevent rotation in the holder, as the edge is on the centerline. The PH Horn ones won't be that susceptible to this. Finally you want to make sure that the back side of a "solid" carbide endmill is actually carbide. Just balance it on your finger...the flute side should be lighter than the shank side. Most of them are not as solid as the name implies....
This is terrific Stefan! I'll have to give it a try with my D-bit grinder. On that topic, I'd love to know how you dress your resin-bonded diamond wheels on that grinder. I might just have to spend a little more and get some name-brand diamond cup-wheels, so far all I have is the Chinese one it came with and that one hammers the work quite a bit. But trying one of these will be a good reason for me to get back to some of the tuning I still have to do on that machine :)
very good tutorial, i also had to buy a dbit grinder after the introduction to it a few months back. this one helped clear up some clouds i had in my head. any word on the electronic lead screw upgrade you did? i would very much like to see that. thanks again for your time making these videos.
Stefan have you consider milling a flat on the bushing opposite the set screw? You could then just push the flat against the wheel to set your reference before clamping down on the collet. It would be like using the face of a chuck to re-align a qctp.
Thanks for the video. It was very interesting. I would also like to see more videos on using the single lip cutter grinder. Do you know of a supplier of the older style 16mm deckel collets?
Horn inserts are quite something for sure, the quality is just beyond and still unmatched by other vendors. we use them in our shop regularily, the smallest one is for 0.3 mm ID upwards. if only they were not expensive as fuck, the other insert we have with CBN for 6 mm ID upwards at 15 mm depth for hardenend steel clocks at around 80 euros without discount... great vid and tremendous job on the grinding, you should really consider doing edge radius tho.
I’m trying to dip my toes into skiving for a very tiny and delicate little lathe part. I was wondering if you have ever tried it and if you had any insight into grinding the cutters.
Is it wrong that I'd buy one of those bits ground by Stefan over one off-the-shelf? The surface finish looks really good....but I suspect it may not be quite as good with my own lathe. Maybe Stefan could send me one to test! ;-D
Stefan, it seems to me that you could somewhat increase the stiffness, or get a deeper eccentric for the same stiffness, by grinding a larger radius on the eccentric portion. For clearance, the radius on the eccentric cut doesn't have to be any less than the radius of the blank. You would end up with an (American) football-shaped cross section on the shaft. The downside, I guess, is that you would leave less room for chips to flee.
Yes, there are many possibilities to make them more suitable for certain tasks. Just play around in cad and see how cross sections and clearances change :)
Hi Stefan, how would you explain inconsistent reflection (shape of ID?) observed at 27:25 ? My first guess was its because of chuck squeeze, but it was already squeezed during cutting, so in the end should be perfectly round right?
Why didn't you made the relieve more eccentric? (Rotation point outside the shaft like in the original Horn boring bars) With this there would be more material in the stressed parts and less grinding.
@@StefanGotteswinter Thank you! I've never really understood the use of these, but this video is an easy sell! Looks like a super handy piece of equipment to have in the shop!
Hello Stefan, I have a Deckel SO grinder and I can't figure out how to do what you did at movie time 19:45, to grind the back relief angle. I am not able to swing the joint beyond 0 deg.(to the left) Do you know if is't this possible with Deckel SO? I have checked the bottom side of the joint, there are two 5mm hex sockets for adjustment but suppose those are for fine adjustment of the end stop of the joint Thank you, Laszlo
@@StefanGotteswinter I hope someone from Siemens PLM is watching your videos and will eventually figure out how beneficial would it be if their software appeared in your videos.
Has anyone ever thought of putting a blind hole trough shaft of boring bar? I mean pipes are tougher to bend than a full peace of steel.Might be something worthy of trying.
With the geometry you gave it (and the fact that it is solid carbide), shouldn't it *theoretically* be possible to plunge these boring bars directly into unbored workpieces? Theoretically. Kind of like a parting tool... but axial...? Sorry if I'm sounding like a complete noob (which I am).
Yes, that works within certain limitations. In plastic and soft metals like aluminium I do that often, in steel its very demanding on the tool and its alignment. But yes, absolutely possible - people like pHorn even sell miniature boring tools that are designed to drill and bore.
@@StefanGotteswinter I've also been wondering if the _sole_ purpose of the "eccentric section" is to ensure that there is nothing behind the "½-diameter flat head section" that can rub against the inside of the bore. _If_ that is the case, then must the boring bar be clamped such that it is parallel to the axis of rotation of the lathe chuck? In other words- the boring bar is obviously _fed_ *straight into* the workpiece when it is used, but must it also be _clamped_ that way? What if it was clamped at a slight angle? (anti-clockwise by a few degrees) Then there wouldn't _be_ anything to rub against the "inner wall" of the bore no matter how far in you went. Right?
